KR20070018230A - Display device - Google Patents

Abstract

The present invention relates to a display device. A display device according to the present invention comprises: a first electrode formed on a substrate material; A light emitting layer formed on the first electrode; A second electrode formed on the light emitting layer; A moisture absorption film formed on the second electrode; It characterized in that it comprises a heat conductive layer formed on the moisture absorption film. As a result, a light emitting layer is properly protected from moisture, and a display device having excellent heat dissipation performance is provided.

Description

Display {DISPLAY DEVICE}

1 and 2 are cross-sectional views of a conventional display device;

3 is a cross-sectional view of a display device according to a first embodiment of the present invention;

4 is a cross-sectional view of a display device according to a second exemplary embodiment of the present invention.

Explanation of Signs of Major Parts of Drawings

11 substrate material 21 pixel electrode

31: partition 41: light emitting layer

51: common electrode 61: first protective film

62: second protective film 71: hygroscopic film

81: heat conductive layer 91: reinforcing substrate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly, to a display device having excellent heat dissipation performance by forming a moisture absorbing film and a heat conductive layer on a light emitting layer, while protecting the light emitting layer from moisture.

BACKGROUND OF THE INVENTION Organic light emitting diodes (OLEDs) have been in the spotlight recently due to advantages such as low voltage driving, light weight, wide viewing angle, and high-speed response among flat panel displays. OLEDs are classified into a passive matrix and an active matrix according to the driving method. The passive type has a simple manufacturing process, but the power consumption increases rapidly as the display area and resolution increase. Therefore, the passive type is mainly applied to small displays. Active type, on the other hand, has a complex manufacturing process but has the advantage of realizing a large screen and high resolution.

1 and 2 show a conventional display device.

The conventional display device 100a illustrated in FIG. 1 includes a substrate material 110, a partition wall 130 that separates the pixel electrode 120 and the pixel electrode 120 formed on the substrate material 110, and a pixel. The light emitting layer 140 on the electrode 120 and the common electrode 150 formed on the light emitting layer 140 are included. The performance and lifespan of the light emitting layer 140 is sensitive to moisture, and is typically encapsulated with a canister 160 manufactured using soda-lime glass to be protected from moisture. The canister 160 and the substrate material 110 are bonded to each other by using an ultraviolet curing adhesive 170, and an absorbent 180 is attached to an inner wall of the canister 160. The space surrounded by the canister 160 and the substrate material 100 is usually filled with nitrogen.

In the conventional display device 100b illustrated in FIG. 2, the moisture absorbent 180 is not attached to the inner wall of the canister 160 and covers the upper portion of the common electrode 150.

Since the conventional display apparatuses 100a and 100b use the canister 160, an additional cost is added, and a separate space for installing the moisture absorbent 180 is required. Since the permeability of the ultraviolet ray hardening adhesive 170 is high as 40 g / m ² day, external moisture cannot be effectively blocked. In addition, since a large amount of heat is generated when the display apparatuses 100a and 100b are driven, heat generation is difficult because heat generated must pass nitrogen having a small thermal conductivity.

Accordingly, an object of the present invention is to provide a display device having excellent heat dissipation performance while the light emitting layer is properly protected from moisture.

An object of the present invention is a first electrode formed on a substrate material; A light emitting layer formed on the first electrode; A second electrode formed on the light emitting layer; A moisture absorption film formed on the second electrode; It is achieved by a display device including a heat conductive layer formed on the moisture absorption film.

The thermally conductive layer preferably includes at least one selected from the group consisting of metals, carbon nanotubes, and diamond-like carbons.

It is preferable that the thickness of the said heat conductive layer is 100 kPa-500 micrometers.

The thermally conductive layer includes carbon nanotubes and silver paste, and is preferably formed by spin coating, chemical vapor condensation, or inkjet printing.

The thermal conductive layer includes diamond-like carbon, and is preferably formed by sputtering, chemical vapor deposition, or electron beam deposition.

The moisture absorption film preferably contains at least one selected from the group consisting of CaO, Ca, Ba, BaO, Mg, MgO and AlO.

It is preferable that the visible light transmittance of the said moisture absorption film is 40 to 90%.

It is preferable that the thickness of the said moisture absorption film is 10 kPa-1 mm.

The moisture absorption film is preferably formed by sputtering or electron beam deposition.

It is preferable to further include a first protective film located between the second electrode and the moisture absorption film, and a second protective film located between the moisture absorption film and the heat conductive layer.

The visible light transmittance of the first protective film and the second protective film is preferably 40 to 100%, respectively.

At least one of the first protective film and the second protective film is preferably made of one or more selected from the group consisting of SiO, SiN, SiON, MgO, AlO.

It is preferable that the water vapor transmission rate of the said inorganic film is 1 g / m <2> days or less.

The inorganic film is preferably formed using sputtering, chemical vapor deposition or electron beam deposition.

At least one of the first protective film and the second protective film is preferably an organic film made of polyacetylene or polyimide.

It is preferable that the water vapor transmission rate of the said organic film is 60 g / m <2> days or less.

The organic layer is preferably formed by a method of spin coating, chemical vapor condensation or inkjet printing.

It is preferable that the thickness of the said 1st protective film and said 2nd protective film is 1-500 micrometers, respectively.

It is preferable to further include a reinforcing substrate formed on the heat conductive layer.

It is preferable to further include a thermal conductive film attached to the outside of the reinforcing substrate.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

In various embodiments, like reference numerals refer to like elements, and like reference numerals refer to like elements in the first embodiment and may be omitted in other embodiments.

3 is a cross-sectional view illustrating a display device according to a first exemplary embodiment of the present invention.

In the display device 1 according to the present invention, the first passivation layer 61, the moisture absorption layer 71, the second passivation layer 62, and the thermal conductive layer 81 are sequentially formed on the emission layer 41. Do not use.

Looking at it in detail as follows.

The pixel electrode 21 is formed on the substrate material 11. The pixel electrode 21 may be made of a transparent conductive material such as indium tin oxide (ITO), and are arranged in a matrix form in plan view. Each pixel electrode 21 is electrically connected to a switching element (not shown), for example a thin film transistor.

A partition wall 31 is positioned between each pixel electrode 21. The partition wall 31 defines a space in which the light emitting layer 41 is to be formed, and also prevents the thin film transistor and the common electrode 51 from being short-circuited. The partition wall 31 may be formed of a photoresist having heat resistance and solvent resistance, such as an acrylic resin and a polyimide resin, or an inorganic material such as SiO 2 or TiO 2, and may have a two-layer structure of an organic layer and an inorganic layer.

The light emitting layer 41 is formed on the pixel electrode 21 surrounded by the partition 31. Holes transferred from the pixel electrode 21 and electrons transferred from the common electrode 51 are combined in the emission layer 41 to form excitons, and then generate light in the process of deactivating excitons. Although not shown, a hole injection layer and / or a hole transport layer may be further included between the light emitting layer 41 and the pixel electrode 21, and an electron injection layer and / or electron between the light emitting layer 41 and the common electrode 51. It may further include a transfer layer.

The illustrated light emitting layer 41 is of a polymer type and may be formed by an inkjet method. The light emitting layer 41 is a polyfluorene derivative, a (poly) paraphenylene vinylene derivative, a polyphenylene derivative, a polyvinylcarbazole, a polythiophene derivative, or a polymeric material of perylene-based dyes, a laumine-based pigment, or a lu thereof. Bren, perylene, 9,10-diphenylanthracene, tetraphenylbutadiene, nile red, coumarin 6, quinacridone and the like can be used.

If the light emitting layer 41 is a low molecular organic material type rather than a polymer type, the light emitting layer 41 may be formed by an evaporation method.

In the case where the light emitting layer 41 is a polymer or a low molecular organic material, unlike the inorganic material, since the performance and life of the light emitting layer 41 are greatly influenced by moisture and oxygen, the light emitting layer 41 should be properly protected from moisture and oxygen.

The common electrode 51 is positioned on the partition 31 and the light emitting layer 41. The common electrode 51 is also called a cathode and supplies electrons to the light emitting layer 41. The common electrode 51 may be formed by stacking a calcium layer and an aluminum layer or a barium layer and an aluminum layer.

The first passivation layer 61 and the second passivation layer 62 positioned on the common electrode 51 and having the moisture absorption layer 71 therebetween prevent moisture and oxygen from penetrating into the light emitting layer 41. Specifically, the first passivation layer 61 serves to finally block water and oxygen that are not blocked by the second passivation layer 62 and the moisture absorption layer 71, and the second passivation layer 62 is moisture that enters from the outside. It primarily blocks oxygen and oxygen.

The passivation layers 61 and 62 may be made of an inorganic layer or an organic layer. One of the protective films 61 and 62 may be an inorganic film and the other may be an organic film.

As the inorganic film, a single film such as SiO, SiN, SiON, MgO, AlO, AlN, TiO, or a mixture of these materials can be used. The inorganic film forming method includes sputtering, chemical vapor deposition, and electron beam deposition, which are vacuum deposition methods. It is preferable that the thickness is 100 mW to 500 m, and the water vapor transmission rate is 1 g / m ² or less. The transmittance of visible light is 40 to 100%.

As the organic film, a polyacetylene or polyimide base material may be used. The organic film forming method may be spin coating, chemical vapor condensation, or inkjet printing. It is preferable that thickness is 1 micrometer-500 micrometers, and water vapor transmission rate is 60 g / m <^2> or less. The transmittance of visible light is 40 to 100%.

The moisture absorption film 71 serves as a reservoir of moisture and oxygen, and uses Ca, CaO, Ba, BaO, Mg, MgO, AlO, and the like. The formation method may be sputtering, an electron beam deposition method, or the like which is a vacuum deposition method. The thickness ranges from 10 mm to 1 mm, and the transmittance of visible light is controlled between 40 and 90% depending on whether the display element 1 is a bottom emission method or a top emission method.

The thermal conductive layer 81 is formed on the second protective film 62. The thermal conductive layer 81 serves to effectively absorb and emit joule heat generated in the light emitting layer 41 and the like. The thermally conductive layer 81 may use a metal having a high thermal conductivity, for example, a mixture of Ag, Cu, Al, and Au, and in particular, a thermally conductive adhesive or diamond-like carbon in which carbon nanotubes and a silver paste are mixed. like carbon) can be used. The thickness of the thermal conductive layer 81 is 100 kPa to 500 µm, and the forming method may be spin coating, chemical vapor condensation, inkjet printing, or screen printing. In particular, the diamond-like carbon thin film may use sputtering, chemical vapor deposition, or electron-beam deposition.

Since thermal conductivity (k) is proportional to the heat passing through, using Ag, Cu, Al, Au, carbon nanotubes, or diamond-like carbon, which are metals having high heat passing, is advantageous for heat dissipation of the display device 1. Since the display device 1 shown in FIG. 1 is a device using a current, the heat generated therein is further increased when the screen size is enlarged. Thus, the heat conduction layer 81 is formed to effectively dissipate heat.

The reinforcing substrate 91 is provided on the heat conductive layer 81. The reinforcing substrate 91 is made of plastic or glass and protects the device from external shocks.

In the display device 1 according to the first exemplary embodiment, the light emitting layer 41 is not exposed to moisture and oxygen due to the application of the protective layers 61 and 62 and the moisture absorbing layer 71, thereby increasing its lifespan and providing excellent display quality. At the same time, the heat conduction layer 81 is applied to effectively release heat generated from the inside to the outside. In addition, since a separate canister is not used, the manufacturing cost of the display device 1 is reduced, and the thickness of the display device 1 can be made thin, for example, 1 mm or less.

4 is a cross-sectional view of the display device 1b according to the second embodiment of the present invention. The difference from the display device 1a according to the first embodiment will be described below.

In the display device 1b according to the second embodiment, the passivation layer 63 is provided as a single layer and is positioned between the common electrode 51 and the moisture absorption layer 71. The protective film 63 is preferably thicker than the first protective film 61 and the second protective film 62 of the first embodiment. As the material of the protective film 63, inorganic materials such as SiO, SiN, SiON, MgO, AlO, AlN, TiO, and organic materials such as polyacetylene and polyimide may be used.

On the other hand, a heat conductive film 92 is attached to the outer surface of the reinforcing substrate 91. The thermal conductive film 92 serves to dissipate heat transferred to the reinforcing substrate 91 to the outside. The thermal conductive film 92 may be in the form of a thermal pad or a tape, and may be made of carbon.

Although some embodiments of the invention have been shown and described, those skilled in the art will recognize that modifications can be made to the embodiments without departing from the spirit or principles of the invention. . It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

As described above, according to the present invention, a display device having excellent heat dissipation performance is provided while the light emitting layer is adequately protected from moisture.

Claims (20)

A first electrode formed on the substrate material; A light emitting layer formed on the first electrode; A second electrode formed on the light emitting layer; A moisture absorption film formed on the second electrode; And a heat conductive layer formed on the moisture absorbing layer. The method of claim 1, The thermal conductive layer includes at least one selected from the group consisting of metals, carbon nanotubes, and diamond-like carbons. The method of claim 1, And a thickness of the thermal conductive layer is 100 mW to 500 m. The method of claim 1, The heat conductive layer includes carbon nanotubes and silver paste, Display device, characterized in that formed by spin coating, chemical vapor condensation or inkjet printing method. The method of claim 1, The thermal conductive layer comprises diamond-like carbon, A display device, characterized in that formed by sputtering, chemical vapor deposition, or electron beam deposition. The method of claim 1, The moisture absorbing film includes at least one selected from the group consisting of CaO, Ca, Ba, BaO, Mg, MgO and AlO. The method of claim 1, And a visible light transmittance of the hygroscopic film is 40 to 90%. The method of claim 1, The thickness of the moisture absorption film is 10Å to 1mm display device. The method of claim 1, The moisture absorption film is formed by sputtering or electron beam deposition. The method of claim 1, And a second passivation layer positioned between the second electrode and the moisture absorption layer, and a second passivation layer positioned between the moisture absorption layer and the heat conductive layer. The method of claim 10, And a visible light transmittance of the first passivation layer and the second passivation layer, respectively, of 40 to 100%. The method of claim 10, At least one of the first protective film and the second protective film is an inorganic film comprising at least one selected from the group consisting of SiO, SiN, SiON, MgO, and AlO. The method of claim 12, The moisture permeability of the inorganic film is less than 1g / ㎡ day (day) display device. The method of claim 12, And the inorganic layer is formed by sputtering, chemical vapor deposition, or electron beam deposition. The method of claim 10, At least one of the first protective film and the second protective film is an organic film made of polyacetylene or polyimide. The method of claim 15, And a water vapor transmission rate of the organic layer is 60 g / m 2 or less. The method of claim 15, And the organic layer is formed by spin coating, chemical vapor condensation, or ink jet printing. The method of claim 10, And a thickness of each of the first passivation layer and the second passivation layer is 1 to 500 μm. The method of claim 1, And a reinforcing substrate formed on the thermally conductive layer. The method of claim 19, And a thermal conductive film attached to an outside of the reinforcing substrate.

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